Warmer oceans of the past fueled fast growth in coral reef fish, reveals study

Scientists at James Cook University have made a fascinating discovery about the growth rates of coral reef fish in the past. According to a study published in the journal Nature, researchers found that these fish developed faster growth rates in the warm oceans of 50 to 60 million years ago. These small, fast-growing fish exemplify the vibrant coral reefs we see today.

The study, co-led by Postdoctoral researcher Dr. Alexandre Siqueira and Ph.D. candidate Helen Yan, explored the evolution of growth rates in coral reef fish over time. They observed that over millions of years, these fish tended to grow faster and reach smaller sizes.

The researchers noted that these abilities first evolved during a period when global temperatures were significantly warmer. The elevated temperatures during that time pushed the boundaries of small fish on reefs, leading to a “live-fast, die-young” lifestyle with some of the fastest growth rates in the animal kingdom.

One example highlighted in the study is the pygmy goby, which has the shortest lifespan of any vertebrate. This fish reaches its full adult size in just over a month and lives for less than eight weeks. These fast-growing fish are abundant on coral reefs and contribute to the high productivity of these ecosystems.

The authors explained that this dynamic lifestyle emerged before the formation of the reefs we know today. Corals, which started building reefs later on, likely provided the necessary cover for many small-bodied, fast-growing fish. The warmer temperatures during that period drove the evolution of faster growth rates, while the subsequent rise of reefs allowed these faster lifestyles to persist.

The study’s findings also raise concerns about the current rates of human-induced climate change. The researchers suggest that warmer waters due to climate change might lead to smaller, faster-growing fish. This implies that ongoing global warming could directly impact fish life strategies.

Overall, this study provides valuable insights into the historical evolution of coral reef fish growth rates and highlights the potential effects of climate change on these vital ecosystems.

Source: James Cook University

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